Computer modules with small thicknesses and associated methods of manufacturing

ABSTRACT

Computer modules with small thicknesses and associated methods of manufacturing are disclosed. In one embodiment, the computer modules can include a module substrate having a module material and an aperture extending at least partially into the module material. The computer modules can also include a microelectronic package carried by the module substrate. The microelectronic package includes a semiconductor die carried by a package substrate. At least a portion of the semiconductor die extends into the substrate material via the aperture.

TECHNICAL FIELD

The present disclosure is related to computer modules carryingmicroelectronic packages with a plurality of semiconductor dies andassociated methods of manufacturing.

BACKGROUND

Today's computer systems typically include a motherboard with aplurality of sockets spaced apart from one another for receiving memorymodules, network interface cards, video cards, and/or other suitablecomputer modules. Such computer modules can include a printed circuitboard that carries one or more microelectronic packages on a surface ofthe printed circuit board. The microelectronic packages typicallyinclude a substrate carrying one or more semiconductor dies encapsulatedin a protective covering.

Stacking a plurality of dies in the microelectronic packages is atechnique for increasing the processing power of the computer modules.However, stacking the dies also increases the thickness of the computermodules by increasing the extension of the microelectronic packages fromthe surface of the printed circuit board. As a result, the limitedspacing between adjacent sockets may be insufficient for accommodating alarge number of stacked dies in the microelectronic packages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a computer module inaccordance with embodiments of the disclosure.

FIG. 2 is a cross-sectional view of the computer module in FIG. 1 asassembled in accordance with an embodiment of the disclosure.

FIG. 3 is a cross-sectional view of the computer module in FIG. 1 asassembled in accordance with another embodiment of the disclosure.

FIG. 4 is a cross-sectional view of the computer module in FIG. 1 asassembled in accordance with yet another embodiment of the disclosure.

FIG. 5 is a cross-sectional view of the computer module in FIG. 1 asassembled in accordance with a further embodiment of the disclosure.

DETAILED DESCRIPTION

Specific details of several embodiments of the disclosure are describedbelow with reference to computer modules with small thicknesses andassociated methods of manufacturing. The computer modules can carry atleast one microelectronic package having a plurality of stacked dies.Typical microelectronic packages include microelectronic circuits orcomponents, thin-film recording heads, data storage elements,microfluidic devices, and other components manufactured onmicroelectronic substrates. Micromachines and micromechanical devicesare included within this definition because they are manufactured usingtechnology similar to that used in the fabrication of integratedcircuits. Microelectronic substrates can include semiconductor pieces(e.g., doped silicon wafers or gallium arsenide wafers), non-conductivepieces (e.g., various ceramic substrates), or conductive pieces. Aperson skilled in the relevant art will also understand that thedisclosure may have additional embodiments, and that the disclosure maybe practiced without several of the details of the embodiments describedbelow with reference to FIGS. 1-5.

FIG. 1 is an exploded perspective view of a computer module 100 inaccordance with embodiments of the disclosure. As shown in FIG. 1, thecomputer module 100 can include a module substrate 102 carrying a firstmicroelectronic package 104 a and a second microelectronic package 104 b(collectively referred to as microelectronic packages 104). As shown inFIG. 1, the module substrate 102 can include a substrate material 103having an aperture 110, a plurality of bond sites 112 proximate to theaperture 110, a plurality of contact pads 114 for electrically couplingwith a computer socket (not shown), and a plurality of optionalsupporting electronic components 116 (e.g., resistors, capacitors,diodes, etc.).

In certain embodiments, the substrate material 103 can include a printedcircuit board that has a first surface 106 a opposite a second surface106 b and a first edge 108 a opposite a second edge 108 b. The first andsecond edges 108 a and 108 b extend between the first and secondsurfaces 106 a and 106 b. In the illustrated embodiment, the substratematerial 103 includes a sheet-like structure with a generallyrectangular shape. In other embodiments, the substrate material 103 caninclude other types of structure with other desired shapes. Even thoughthe substrate material 103 is shown in FIG. 1 as a single layer ofmaterial, in certain embodiments, the substrate material 103 can alsoinclude a plurality of conductive and/or non-conductive layers laminatedand/or otherwise combined with one another.

The aperture 110 can be shaped and sized to accommodate at least aportion of the microelectronic packages 104. In the illustratedembodiment, the aperture 110 has a generally rectangular cross-sectionand extends between the first and second surfaces 106 a and 106 b of thesubstrate material 103 at a depth D. As a result, the depth D of theaperture 110 generally equals to the thickness of the module substrate102. In other embodiments, the aperture 110 can have a steppedcross-section, a curved cross-section, a partially curved cross-section,and/or other suitable cross-sectional geometries corresponding to thegeometry of the microelectronic packages 104. In yet furtherembodiments, the aperture 110 may extend only partially between thefirst and second surfaces 106 a and 106 b with a depth that is less thanD. The aperture 110 may be formed by cutting, punching, etching, and/orother suitable techniques for removing a portion of the substratematerial 103.

The microelectronic packages 104 can include a package substrate 118carrying one or more semiconductor dies 130 (not shown in FIG. 1)encapsulated in an encapsulant 120. As shown in FIG. 1, the packagesubstrate 118 can include a first surface 119 a generally facing themodule substrate 102 and a second surface 119 b opposite the firstsurface 119 a. The first surface 119 a includes a peripheral portion 118b that extends laterally from a central portion 118 a. The centralportion 118 a can generally correspond to the semiconductor dies 130encapsulated in the encapsulant 120. The encapsulant 120 with theencapsulated semiconductor dies 130 can extend from the first surface119 a for a height d. The peripheral portion 118 b can carry a pluralityof contact pads 122 in electrical communication with the semiconductordies 130. In the illustrated embodiment, the microelectronic packages104 are generally similar in structure and in function. In otherembodiments, the microelectronic packages 104 can have differentstructure and/or function. In further embodiments, one of themicroelectronic packages 104 may be omitted, as described in more detailbelow with reference to FIGS. 4 and 5.

In certain embodiments, the depth D of the aperture 110 can be largerthan twice the height d of the encapsulant 120 with the encapsulatedsemiconductor dies 130 as follows:

D≧2d

As a result, the encapsulated semiconductor dies 130 of both themicroelectronic packages 104 can be completely inside the aperture 110of the substrate module 102. In other embodiments, the depth D of theaperture 110 can be larger than the height d of the encapsulant 120 withthe encapsulated semiconductor dies 130 but less than twice the height das follows:

2d>D≧d

As a result, in certain embodiments, the encapsulated semiconductor dies130 of both the microelectronic packages 104 can be partially inside theaperture 110. In other embodiments, the encapsulated semiconductor dies130 of one microelectronic package 104 may be substantially inside theaperture 110, and those of the other microelectronic package 104 may beonly partially inside the aperture 110. In further embodiments, thedepth D of the aperture 110 can be less than the height d of theencapsulant 120 with the encapsulated semiconductor dies 130 as follows:

D<d

As a result, the encapsulated semiconductor dies 130 of themicroelectronic packages 104 may be partially inside the aperture 110.

During assembly, a plurality of electric couplers 124 (e.g., solderbumps, gold bumps, etc., not shown in FIG. 1) can be disposed onto theindividual bond sites 112 and/or the contact pads 122. Themicroelectronic packages 104 can then be positioned relative to themodule substrate 102 by (1) at least partially inserting theencapsulated semiconductor dies 130 into the aperture 110; and (2)aligning the individual contact pads 122 with the corresponding bondsites 112 on the module substrate 102. Subsequently, the electriccouplers 124 may be reflowed and/or otherwise processed to electricallycouple the bond sites 112 of the module substrate 102 with thecorresponding contact pads 122.

Several embodiments of the computer module 100 can have a reducedthickness when compared to conventional computer modules. By at leastpartially inserting the microelectronic packages 104 into the aperture110 of the module substrate 102, the microelectronic packages 104 canhave a reduced height from the first and/or second surfaces 106 a and106 b of the module substrate 102. Accordingly, the microelectronicpackages 104 may incorporate a larger number of stacked semiconductordies 130 with a reduced impact on the thickness of the computer module100 when compared to conventional computer modules.

Even though the computer module 100 is shown in FIG. 1 as having oneaperture 110, in other embodiments, the computer module 100 can havetwo, three, four, or any other desired number of apertures 110 toaccommodate corresponding microelectronic packages 104. In certainembodiments, some of the apertures 110 may have different shape, size,and/or other characteristics than the other apertures 110. In otherembodiments, all of the apertures 110 may be generally identical to oneanother. In further embodiments, the microelectronic packages 104 may beelectrically coupled to the module substrate 102 using wirebonds,leadframes, and/or other suitable techniques.

FIGS. 2-5 are cross-sectional views of the computer module 100 in FIG. 1as assembled in accordance with several embodiments of the disclosure.As shown in FIG. 2, the computer module 100 includes the microelectronicpackages 104 coupled to a first side 102 a and a second side 102 b ofthe substrate module 102 with a plurality of electric couplers 124. Theelectric couplers 124 can include solder balls, solder bumps, goldbumps, and/or other suitable conductive couplers. The microelectronicpackages 104 can include a plurality of semiconductor dies 130 attachedto the package substrate 118 and to one another with an adhesive layer132 in a stacked arrangement. A plurality of wirebonds 134 electricallycouple bond sites 136 of the individual semiconductor dies 130 tocorresponding terminals 137 on the package substrate 118. Thesemiconductor dies 130 can include DRAM, VRAM, FPRAM, and/or othersuitable types of semiconductor dies. Even though four semiconductordies 130 are shown for illustration purposes, the microelectronicpackages 104 may include one, two, three, five, or any other desirednumber of semiconductor dies 130. In other embodiments, the plurality ofsemiconductor dies 130 may be coupled to the package substrate 118and/or to one another in a flip-chip arrangement and/or other suitablearrangements.

In certain embodiments, the microelectronic packages 104 individuallyinclude a processor die 138 encapsulated in the encapsulant 120. In theillustrated embodiment, the processor die 138 is electrically coupled toone of the semiconductor dies 130 with a plurality of conductivecouplers 142 (e.g., solder balls). In other embodiments, the processordie 138 may be coupled to the second surface 119 b of the packagesubstrate 118 as shown in FIG. 3. In further embodiments, the processordie 138 may be omitted.

In the embodiment shown in FIG. 2, the depth D of the aperture 110 isgreater than twice the distance d of the encapsulant 120 and theencapsulated semiconductor dies 130. The semiconductor dies 130, theprocessor dies 138, and the encapsulant 120 of the microelectronicpackages 104 are substantially disposed inside the aperture 110 in aface-to-face configuration. Even though a gap 146 is shown in FIGS. 2and 3 between the microelectronic packages 104, in certain embodiments,top surfaces 105 of the microelectronic packages 104 may abut eachother.

In another embodiment, as shown in FIG. 4, the computer module 100 mayinclude only one microelectronic package 404 that substantially occupiesthe entire space in the aperture 110. The microelectronic package 404can be generally similar to the microelectronic packages 104 of FIG. 2except that the microelectronic package 404 can include moresemiconductor dies 130 than the microelectronic packages 104 of FIG. 2.In the illustrated embodiment, the top surface 105 of themicroelectronic package 404 is generally flush with the second side 102b of the substrate module 102. In other embodiments, the top surface 105of the microelectronic package 404 can be recessed from the second side102 b of the module substrate 102. In further embodiments, the topsurface 105 can extend beyond the second side 102 b of the substratemodule 102. Even though the microelectronic package 404 is shown toinclude eight semiconductor dies 130, in other embodiments, themicroelectronic package 404 can include any desired number ofsemiconductor dies 130. In further embodiments, the microelectronicpackage 404 can include the processor die 138 electrically coupled tothe second surface 119 b of the package substrate 118 generally similarto that shown in FIG. 3.

In further embodiments, as shown in FIG. 5, the computer module 100 caninclude a microelectronic package 504 electrically coupled to a modulesubstrate 502. The module substrate 502 can be generally similar instructure and in function as the module substrate 102 shown in FIGS.1-4. However, the module substrate 504 can include a recess 103 at thefirst side 102 a and the bond sites 112 disposed in the recess 103. Inthe illustrated embodiment, the recess 103 is sized and shaped toreceive the package substrate 118 such that the second surface 119 b ofthe package substrate 118 is generally flush with the first side 102 aof the module substrate 504. In other embodiments, the recess 103 may besized and shaped such that the package substrate 118 is recessed from orextending beyond the first side 102 a.

As shown in FIG. 5, the microelectronic package 504 can include aplurality of semiconductor dies 130 encapsulated in an encapsulant 520having an opening 521. The microelectronic package 504 can also includea plurality of electronic components 516 electrically coupled to thesemiconductor die 130 through the opening 521 with conductive couplers517 (e.g., solder balls). The electronic components 516 can includeresistors, capacitors, and/or other suitable electronic componentsconfigured for signal/power filtering, power rectifying, and/or othersignal or power processing functions. Without being bound by theory, itis believed that the short distance between the semiconductor dies 130and the electronic components 516 can improve the quality of signaland/or power processing by at least partially reducing transmissioninterference.

Even though the module substrate 502 is shown to have the recess 103 onthe first side 102 a, in other embodiments, the module substrate 502 mayinclude the recess 103 on the second side 102 b. In further embodiments,the module substrate 502 may include the recess 103 on the first side102 a and another recess (not shown) on the second side 102 b. In yetfurther embodiments, the recess 103 may be omitted.

From the foregoing, it will be appreciated that specific embodiments ofthe disclosure have been described herein for purposes of illustration,but that various modifications may be made without deviating from thedisclosure. In addition, many of the elements of one embodiment may becombined with other embodiments in addition to or in lieu of theelements of the other embodiments. Accordingly, the disclosure is notlimited except as by the appended claims.

1. A computer module, comprising: a printed circuit board having a firstsurface, a second surface opposite the first surface, and an apertureextending between the first and second surfaces, the printed circuitboard including a plurality of bond sites proximate to the aperture; anda microelectronic package having a semiconductor die and a packagesubstrate carrying the semiconductor die, the package substrate having aplurality of contact pads individually aligned with the bond sites ofthe printed circuit board, wherein at least a portion of thesemiconductor die is inside the aperture of the printed circuit board.2. The computer module of claim 1 wherein the bond sites are a firstplurality of bond sites on the first surface; the printed circuit boardfurther includes a second plurality of bond sites on the second surface;the microelectronic package is a first microelectronic package having afirst plurality semiconductor dies encapsulated in a first encapsulantand carried by a first package substrate, the plurality of contact padsbeing a first plurality of contact pads; the computer module alsoincludes a second microelectronic package proximate to the secondsurface of the printed circuit board, the second microelectronic packagehaving a second plurality of semiconductor dies encapsulated in a secondencapsulant, a second package substrate carrying the secondsemiconductor dies, and a second plurality of contact pads; the firstcontact pads are individually generally aligned with the first pluralityof bond sites on the printed circuit board and the second contact padsare individually generally aligned with the second plurality of bondsites on the printed circuit board; and the first and second pluralityof semiconductor dies and the first and second encapsulants aresubstantially completely inside the aperture of the printed circuitboard.
 3. The computer module of claim 1 wherein the bond sites are afirst plurality of bond sites on the first surface; the printed circuitboard further includes a second plurality of bond sites on the secondsurface; the microelectronic package is a first microelectronic packagehaving a first plurality of semiconductor dies encapsulated in a firstencapsulant and carried by a first package substrate, the plurality ofcontact pads being a first plurality of contact pads; the computermodule also includes a second microelectronic package proximate to thesecond surface of the printed circuit board, the second microelectronicpackage having a second plurality of semiconductor dies encapsulated ina second encapsulant, a second package substrate carrying the secondsemiconductor dies, and a second plurality of contact pads; the firstcontact pads are individually generally aligned with the first pluralityof bond sites on the printed circuit board and the second contact padsare individually generally aligned with the second plurality of bondsites on the printed circuit board; and the first and second pluralityof semiconductor dies and the first and second encapsulants aresubstantially completely inside the aperture of the printed circuitboard with the first and second encapsulants abutting each other.
 4. Thecomputer module of claim 1 wherein the microelectronic package includesan encapsulant encapsulating the semiconductor die, and wherein theaperture has a cross-sectional dimension larger than that of theencapsulated semiconductor die.
 5. The computer module of claim 1wherein the microelectronic package includes an encapsulantencapsulating the semiconductor die, and wherein the aperture has across-sectional dimension larger than that of the encapsulatedsemiconductor die but smaller than that of the package substrate.
 6. Thecomputer module of claim 1 wherein the microelectronic package includesan encapsulant encapsulating the semiconductor die, the encapsulatedsemiconductor die having a surface facing away from the packagesubstrate, and wherein the package substrate is attached to the firstsurface of the printed circuit board, and further wherein the surface ofthe encapsulated semiconductor die is generally flush with the secondsurface of the printed circuit board.
 7. The computer module of claim 1wherein the microelectronic package includes an encapsulantencapsulating the semiconductor die, the encapsulated semiconductor diehaving a surface facing away from the package substrate, and wherein thepackage substrate is attached to the first surface of the printedcircuit board, and further wherein the surface of the encapsulatedsemiconductor die is recessed from the second surface of the printedcircuit board.
 8. The computer module of claim 1 wherein themicroelectronic package includes an encapsulant encapsulating thesemiconductor die, the encapsulated semiconductor die having a surfacefacing away from the package substrate, and wherein the packagesubstrate is attached to the first surface of the printed circuit board,and further wherein the surface of the encapsulated semiconductor die isextending beyond the second surface of the printed circuit board.
 9. Thecomputer module of claim 1 wherein the microelectronic package furtherincludes a processor die and an encapsulant encapsulating thesemiconductor die and the processor die, the encapsulated semiconductordie having a surface facing away from the package substrate, and whereinthe package substrate is attached to the first surface of the printedcircuit board, and further wherein the surface of the encapsulatedsemiconductor die is generally flush with the second surface of theprinted circuit board.
 10. The computer module of claim 1 wherein themicroelectronic package includes an encapsulant encapsulating thesemiconductor die, the encapsulant having an opening facing away fromthe package substrate, and wherein the microelectronic package furtherincludes a plurality of electronic components electrically coupled tothe semiconductor die via the opening.
 11. The computer module of claim1 wherein the module substrate includes a recess proximate to theaperture, and wherein the bond sites of the printed circuit board arelocated in the recess.
 12. A computer module, comprising: a modulesubstrate having a module material and an aperture extending at leastpartially into the module material; and a microelectronic packagecarried by the module substrate, the microelectronic package having asemiconductor die carried by a package substrate, wherein at least aportion of the semiconductor die extends into the substrate material viathe aperture.
 13. The computer module of claim 12 wherein the modulesubstrate includes a plurality of bond sites on a surface of the modulesubstrate and adjacent to the aperture, and wherein the microelectronicpackage includes a plurality of contact pads generally aligned with theindividual bond sites.
 14. The computer module of claim 12 wherein themodule substrate includes a plurality of bond sites on a surface of themodule substrate and adjacent to the aperture, and wherein themicroelectronic package includes a plurality of contact pads generallyaligned with the individual bond sites, and further wherein the computermodule includes a plurality of electric couplers between individual bondsites and corresponding contact pads while the semiconductor die extendsinto the substrate material via the aperture.
 15. The computer module ofclaim 12 wherein the aperture has a depth generally equal to a thicknessof the module substrate.
 16. The computer module of claim 12 wherein theaperture has a depth less than a thickness of the module substrate. 17.The computer module of claim 12 wherein the aperture has a depthgenerally equal to a thickness of the module substrate, and wherein thesemiconductor die extends from the package substrate for a distance lessthan the depth of the aperture.
 18. The computer module of claim 12wherein the aperture has a depth generally equal to a thickness of themodule substrate, and wherein the semiconductor die extends from thepackage substrate for a distance less than half of the depth of theaperture.
 19. The computer module of claim 12 wherein the aperture has adepth generally equal to a thickness of the module substrate, andwherein the semiconductor die extends from the package substrate for adistance generally equal to the depth of the aperture.
 20. The computermodule of claim 12 wherein the aperture has a depth generally equal to athickness of the module substrate, and wherein the semiconductor dieextends from the package substrate for a distance longer than the depthof the aperture.
 21. A method for assembling a computer module,comprising: positioning a microelectronic package proximate to a modulesubstrate having a module material and an aperture extending at leastpartially into the module material, the microelectronic package having asemiconductor die carried by a package substrate; generally aligning thesemiconductor die of the microelectronic package with the aperture ofthe module substrate; and extending at least a portion of thesemiconductor die into the substrate material via the aperture.
 22. Themethod of claim 21 wherein the module substrate includes a bond site ona surface of the module substrate and adjacent to the aperture, andwherein the microelectronic package includes a contact pad electricallycoupled to the semiconductor die, and further wherein the methodincludes generally aligning the contact pad with the bond site.
 23. Themethod of claim 21 wherein the module substrate includes a bond site ona surface of the module substrate and adjacent to the aperture, andwherein the microelectronic package includes a contact pad electricallycoupled to the semiconductor die, and further wherein the methodincludes: generally aligning the contact pad with the bond site;disposing an electric coupler between the contact pad and the bond site;and electrically coupling the contact pad and the bond site with theelectric coupler.
 24. A printed circuit board for carrying amicroelectronic package, comprising: a substrate having a first surface,a second surface opposite the first surface, a first side and a secondside opposite the first side, both the first and second sides extendingbetween the first and second surfaces; an aperture located between thefirst and second sides of the substrate and extending between the firstand second surfaces, wherein the aperture is configured to receive atleast a portion of the microelectronic package; a plurality of bondsites proximate to the aperture; and a plurality of contact padsproximate to the first side, the contact pads being configured tointerface with a socket of a motherboard.
 25. The printed circuit boardof claim 24 wherein the aperture extends completely between the firstand second surfaces.
 26. The printed circuit board of claim 24 whereinthe aperture extends completely between the first and second surfaces,the aperture having a generally rectangular uniform cross-sectionbetween the first and second surfaces.
 27. The printed circuit board ofclaim 24 wherein the aperture extends partially between the first andsecond surfaces.